Check out these pics from 1971. What guitar is Jerry playing? The neck looks to be a Gibson, but the body is unlike any I'm familiar with, and it looks to have been modded with some type of brass plate, maybe? (Gee, I wonder who could have done that?)

The body reminds me of the peanut guitar. I found this in a post from Susan in 2004.

"There were other guitars made at Alembic for Jerry, of the first dozen instruments made, 5 were guitars for Jerry. He wanted a guitar that had the smallest body imaginable, I called them "peanut" guitars. Those guitars eventually evolved into the Guitar that later became known as Wolf. BTW we currently have a peanut guitar number 6 made for Jerry that we are refurbishing for sale. "

Here is a link to the thread. There area couple of pictures if you scroll down.

In Grateful Dead Gear Turner describes the first one he built (pre-Alembic); it was the neck off a trashed LP Custom for which he built a Stauffer-shaped body out of mahogany w/walnut veneers. That sounds like this one (check the inlays), and he said he sold it to Jerry, and was "an evolutionary step toward Alembic" - an inspiration for the peanuts, perhaps?